Federal officials are extending legal protection to the eastern massasauga rattlesnake, which inhabits a broad section of the northern and central U.S. but has been in decline for years.

The U.S. Fish and Wildlife Service is listing the snake as "threatened," meaning it's vulnerable to dying out but not in such peril that it's considered "endangered."

The eastern massasauga is seldom seen. It lives in wetland areas from Missouri to New York and parts of the Canadian province of Ontario. Its numbers have fallen as wetlands have been drained for farming and urban development.

Persecution from fearful humans has also hurt.

Elise Bennett of the Center for Biological Diversity says designating the snake as threatened can save habitat it needs to survive.

The snake is among more than 170 species protected under a 2011 settlement between the center and the government.